In the latest diverse electronic products, a touch panel with an inputting method through which a finger or an input device such as a stylus is used to contact an image displayed on a display device is applied.
The touch panel may be divided into a touch panel of a resistive layer type and a touch panel of an electrostatic capacity type. In the touch panel of a resistive layer type, a position is detected when an electrode becomes a short circuit by pressure of an input device. In the touch panel of an electrostatic capacity type, a position is detected when an electrostatic capacity between electrodes is changed by finger contact.
FIG. 1 is a perspective view illustrating a related art capacitive touch panel.
Referring to FIG. 1, a related art capacitive touch panel includes a lower plate 110, a first conductive pattern 140, a first metal electrode 150, an Optically Clear Adhesive (OCA) 120, an upper plate 130, a second conductive pattern 160, and a second metal electrode 170. In more detail, the first conductive pattern 140 is formed on the lower plate 110, and the first metal electrode 150 connected to the first conductive pattern 140 is formed on the lower plate 110. Herein, as illustrated in FIG. 1, a plurality of conductive pattern shapes are connected in one row in the abscissa axis direction and thereby the first conductive pattern 140 is formed. Also, straight-line pattern shapes are spaced apart. Moreover, the second conductive pattern 160 is formed on the upper plate 130, and the second metal electrode 170 connected to the second conductive pattern 160 is formed on the upper plate 130. Herein, the second conductive pattern 160 is vertical to the first conductive pattern 140. Also, the upper plate 130 and the lower plate 110 adhere to each other by the OCA 120.
In the related art touch panel, the first conductive pattern 140 and the first metal electrode 150 are formed on the lower plate 110, and the second conductive pattern 160 and the second metal electrode 170 are formed on the upper plate 130. That is, the first and second conductive patterns 140 and 160 are formed on different layers, and the first and second metal electrodes 150 and 170 are formed on different layers. However, a structure, in which the upper plate 130 and the lower plate 110 are divided and the OCA 120 is used between the upper plate 130 and the lower plate 110, has limitations.
That is, since the residual having viscosity occurs by using the OCA, efficiency of work decreases and the second failure increases. Moreover, transmittance and visibility decrease due to use of the OCA. Furthermore, there is a limitation in reducing the entire thickness of a touch panel.
Moreover, when a conductive transparent layer, particularly, an Indium-Tin Oxide (ITO) film is used, the cost is high and at least two films are required, whereupon there is another limitation in reducing the thickness of the touch panel.